Type the name of the user in the box (without the User: namespace prefix) and click "edit user groups". This displays a list of the groups that you can add or remove. Select the groups, and then press "save user groups".

A local bureaucrat can use this page to grant or revoke bot status to another user account.
Bot status hides a user's edits from recent changes and similar lists, and is useful for flagging users who make automated edits. This should be done in accordance with applicable policies which can be seen at Commons:Bots. Please remind the bot operator to update the lists there after you grant the flag...

Bots requests are found at Commons:Bots/Requests. Once you grant the request, after a short time, the request should be archived at Commons:Bots/Archive in chronological order (newest last). Give a link to the subpage.